Prof. T. Carnelley on the Periodic Law. 

 Table II. — Illustrating Relations 1, 2, 3. 





Chlorides. 



Bromides. 



1 

 Iodides. 



a S 



+3 o 

 © Pa 



•3 



•s * 



pq 



L 



-2d 



«4-. O 



w 



1 



+3 '0 



-Mo 



•3 a 



pq 



W 



fl.fl 



719 

 771 



397 

 420 

 322 

 310 

 264 



a 

 •s ft 

 pq 



u 

 c :£ 



$ B. 

 tfl 



Li 



870 

 874 

 210 

 231 

 200 

 199 

 189 



"296 



351 

 344 

 251 



215 



94000 

 36166 



820 



874 



271 



364? 



244 



237 



218 



"363 



462 

 439 

 346 

 270 



24366 



Be 



B 



493 



620 i 



585 



465 



c 



N 







F 



359 







Na 



1045 



981 

 340 

 205 

 200 

 199 

 198 



"453 

 331 

 351 

 337 

 240 



97700 

 75500 

 52000 

 39400 

 25266 



981 

 971 



366 

 260 



252 

 240 

 229 



"533 



426 

 444 



406 



286 



90600 

 70000 

 42830 

 30100 

 18200 



901 

 896 

 398 

 393 

 328 

 315 

 298 



623 

 563 

 575 



74100 

 54000 

 27870 

 14000 

 8900 



Mff 



Al 



Si 



P 



s 



528 i 

 373 



01 









K 



1007 

 992 

 236 

 246 



"334 



408 



104600 



84800 



972 

 949 

 293 



"407 



99000 



75600 



907 

 904 

 404 

 423 





85200 



Ca 



! 59100 



528 

 633 \ 



Sc 



Ti 



312 1 503 













of each series (the difference between which is comparatively 

 small) to the third member, there is a sudden drop in both 

 melting-point and boiling -point ; whilst, on passing from the 

 third on to the seventh, the decrease is far more gradual. (See 

 Table II. and Plate I.) 



Relation 3. (a) For the third, fourth, fifth, sixth, and 

 seventh groups of elements, the melting-point and boiling-point 

 increase as we pass from the chloride to the bromide and thence 

 to the iodide. 



(b) For the even members of the first and second groups, the 

 opposite relation holds good. 



(c) In all cases the heat of formation diminishes from 

 chlorides to iodides. 



For illustration of the above, see Table II. and Plate L; also 

 Table III., in which are arranged the elements belonging to the 

 fourth, or carbon-group. The even members of the group are 

 printed in ordinary and the odd members in black figures. 

 According to MendeljefF, it is only the odd members which 

 can be strictly compared with the odd, or the even members 

 with the even, and not the odd members with the even ; and 

 this, as will be seen, is fully borne out by a comparison of 

 their melting- and boiling-points. 



